Wire connecter



Sept. 8, 1925. I 1,552,424

E. A. EVERETT v v WIRE CONNECTER Fil ed Jan. 14, 1924 2amuuununuuuuununqmnu Patented Sept.- 8. 1925.

UNITED STATES PATENT OFFICE. 4

EDWARD A. EVERETT, OF NEW YORK, N; Y.

WIRE conimc'rnn.

Application filed January 14, 1924. Serial 110. 685,949.

To all whom it may concern:

Be it known that I, EDWARD A. l lvnnn'i'r; a citizen of the UnitedStates, and resident of New York city, in the county of New York andState of New York, have invented certain new and useful Improvements inWire Connecters, of which the following is a specification.

This invention relates to wire connecters and has for anobject toprovide conn'ec ters of this kind which will maintain a reliablecontactwith unvarying resistance between conductors which are exposed to theelements and which are subject to movement as wires are changed. Thisinvention also includes a resistance wire clamped to a stem which issubject to movement. without changing the position of the resistancewire relative to the stem. These and other objects of the invention willbe understood from the following specification and the accompanyingdrawings in which, Fig. 1, is a halfsectional elevation of a form ofporcelain terminal using my invention, Fig.2 is a bottom plan view ofthe terminal shown in Fig. 1, Fig. 3 is a plan View of another type ofterminal using my invention and Fig. 4 is a sectional elevation of Fig.3, Fig. 5 is a detail of the stem used in carrying out this inventionand Fig. 6 shows its application.

The devices shown in the illustrations are known as terminal blocks andare used to ket for a considerable time and are exten-' sively usedespecially in the circuits controlling railway slgnals.

In practice it has been found that the stem which is clamped to theporcelain base in time becomes loose due to temperature changes and asthe binding screws are unscrewed there is a torsion applied to the stemcausing it to partially rotate in the .porcelain. Before this inventionthe stem clamped the resistance wire against the por- Suitcelainand asthe porcelain has greater friction. than the stem, the stem turned uponthe loop of the resistance wire thus bringing new surfaces into contact.These sur faces are oxidized by pouring the sealing compound around theterminal and the movement just described introduces con siderableresistance and in fact has been known to open the circuit.

This condition is further aggravated byreason of the fact that theresistance wire is made from a special alloy which will not fuse, whichcannot be soldered and which has a. hard scaly surface which must beground off where the connection 1s made and a movement of the wirerelative to the stem is liable to bring part of the unprepared surfaceinto contact with the stem. As this cuit are connected. The base 11 maybe secured to a terminal board by screws through the holes 17 thusforming a fixed terminal to which the wiresare connected.

The resistance coil 18 is placed in the rectangular opening in theporcelain and connects to the stem 20 of the binding posts 13 and 14 sothatthis coil forms-part of the circuit between conductors .15 and16.When the coil is in place it is sealed in the slot 12 by a high meltingpoint sealing wax as indicated at 19. This sealing compound is pouredinto theslot in a liquid state covering the stem and the coil.

The stem of the binding posts is constructed as shown .in Fig.j5 havingboth ends threaded and the square collar 21 as shown. This stem isinserted in the open- .ing in the porcelain base 11 until the collar 21engages the porcelain where it is clamped Terminal binding posts 13 and14 are supported by Hand to these 'posts the conductors 15 and 16 of thecir 22 of the resistance coil 18 is placed against in position by theclamp nut 28. The loop i collar 21, a washer is placed against this loopand the connection is clamped by nut 23. It will thus be observed thatthe connection between coil 18 and stem 20 is clamped and maintained infixed relation without regard to the movement of the stem with relationtothe porcelain base.

Due to variations in temperature, vibration or other causes the clampingnut 28 works loose and the stem 20 is free to turn to the extentpermitted by the square collar 21 abutting against the porcelain wall asindicated in Fig. 6. lVhen the binding nuts work stiffly on stem 20 thecollar turns in the direction of the line aand the line b. It is notpossible to manufacture porcelain with a clos tolerance so that there isvariation in the cores the space between the porcelain and the squarecollar is likely to vary and permit of the turning of the stem to agreater or less degree. By clamping the coil 18 to the end of the stemit is apparent that this part of the coil will move with the stem andthere can be no variation in the resistance of this connection. If theloop 22 were clamped by the collar 21 against the porcelain it isapparent that half the contacting surface of the loop would be madeagainst the porcelain and, as the porcelain is unglazed there would beless friction between the collar and the loop than between the loop andthe porcelain so that the collar would turn on the loop and thus bringnew surfaces into contact. These new surfaces due to oxidizationintroduce a re.- sistance in the connection which it is the purpose ofthe present invention to avoid.

The construction shown in Figs. 1 and 2 include a porcelain terminalblock which may be used to support the lightning ar rester 29 of thetype described in application, Serial No. 485,223, and in which 18becomes a choke coil, however, with the arrester removed, the coil 18becomes a fixed resistance. The construction in Figs. 3 and 4 show theapplication of my invention to a fixed resistance unit in which 31 is aporcelam base, 32, 38, 34 and 35 are binding posts to which theconductors are connected. These binding posts hai e a stem similar tothat shown in Fig. 5. The porcelain base is hollow as indicated by thedotted lines in Fig. 3 and has a central core 36 with a holetherethrough which is used for a fastening screw. A coil connects eachof the terminal posts as indicated at 18 and having a resistance valueindicated by the figures on top of the porcelain shown in Fig. 3. Theseresistances are of comparatively low value and it is important that theyshould not vary in resistance after the lapse of time when used inoutdoor construction on railways and similar exposed places.

I he circuits with which this device is assoclated are usually on pollines or are con;

nected with the track rails. In either case heavy lightning dischargespast through the resistance coil. Frequently these discharges will meltaway the sealing compound and expose the bare coils of the resistanceunit. If ordinary resistance wire were used in the construction of thesecoils they would fuse together under these conditions, thereby de'stroying the resistance and affecting the controlled circuits in such away as might lead to unsaf conditions. On this account the coils aremade of a special alloy wire which will not fuse under heat and whilethe turns of the coil, if exposed, may come into contact when heated,these turns will immediately separate as the coil cools restoring normalconditions. Since this wire will not fuse it cannot be welded by the ordinary methods of construction used in a workshop and it cannot besoldered. The surface of the wire is covered by a hard scale which is,to some extent, an insulator and which has 'to be ground off on the endsthat are used for the connections.

It will thus be observed that the peculiar character of the resistancecoil and the uses for which the device is intended require a specialconnection differing from the ordinary methods of construction and whichare provided for in the present invention in a simple, effective andcomparatively inexpensive manner.

The term resistance coil is used in the specification and claims in ageneric sense.

In one application, this coil is used on direct current circuits Where aconstant ohmic resistance is desired. When used for a choke withlightning arresters, however, it is designed to offer a high resistanceto the lightning discharge, while its ohmic resistance 1 may be very lowand the coil may be made from ordinary copper wire. In the latter casethe lightning arrester is arranged to discharge the lightning underdefinite conditions and an unvarying contact between 0 the post and thecoil is necessary to the maintenance of these conditions.

Having thus. described my invention, I claim:

1. In a wire connecter, the combination of 5 a porcelain base, a stemthreaded at both ends with an integral collar thereon extending throughsaid base, means for clamping said collar against said base, bindingnuts on the exposed end of said stem for clamping a conductor thereto, acoil of resistance wile, a nut for clamping the ends of said coilagainst said collar and a sealing compound for covering the connectionof said coil to said stem.

2. In a wire connecter, the combination of a hollow porcelain base, astem having an integral square collar and threaded at both endsextending through said base, means for clamping said collar against said130 base and for clamping a conductor to the exposed end of said stem, acoil of resistance Wire in said hollow base and a. nut for clamping theend of said coil against said collar.

3. In a wire connecter, the combination of a hollow porcelain base, a.stem having a a porcelain base having a hollow rectangular opening, astem having a square-collar and threaded at both ends, one end extendingthrough an opening in said porcelain base with the square collarengaging the sides of said opening, a nut clamping said stem on saidbase, binding nuts for securing acon ductor to said stem, a coil ofalloy wire in the rectangular opening in said base, the end of said coillooped around the end of said stem, a nut for clamping said wire againstsaid collar and a. sealing compound for covering said stein andsaidcoil.

Signed at New York, in the county of New York and State of New York,this 16th day of November, A. D. 1923'.

EDWARD A. EVERETT.

